Artificial arm



Jan. 17, 1950 R. w. WILKINSON ARTIFICIAL ARM 3 Sheets-Sheet l Filed July251.1947

Jan. 17, 1950 R. w. WILKINSON ARTIFICIAL ARM Filed July 23, 1947 5Sheets-Sheet 2 afldmgmsm Jan. 17, 1950 R. w. WILKINSON ARTIFICIAL ARM NN M M fw n f EM Patented Jan. 17,"l 195() ARTIFICIAL ARM Robert W.Wilkinson, Tisdale, Saskatchewan,

Canada Application July 23, 1947, Serial No. 762,895

8 Claims. (Cl. 3-12) This invention relates to artificial arms and moreparticularly to means for operating the same which utilize relativemovementI between vthe torso and a shoulder of the wearer.

Artificial arms as developed in the prior art generally are operatedthrough wires or suitable strap means passing across the body or overthe lshoulders of the wearer to fasten to or to be actuated by his goodarm. Such mechanisms are cumbersome, their unwieldy nature leading notadvantages evident in mechanisms of the prior art by providing anartificial arm which is operable from one side ofthe body and isindependent of the good arm of the wearer for its actuation.

My invention also has for its object the provision of an artificial armof this class which depends for its operation upon relative movementbetween the torso and the shoulder carrying the "'stump of the wearer,being hereinafter referred to as the adjacent shoulder.

A further object of the present invention is to provide an artificialarm as before, by virtue of which the wearer is capable of lifting aweight 4which he might not be capable of handling with his natural arm.

A still further object of the present invention is to provide anarticial arm which is capable of operation by a wearer even though thewearer has no stump.

With these and other objects in view, the invention generally relates toimprovements in artificial arms of the class having an upper arm memberwith a forearm member hingedly connected thereto and leverage meansassociated with the forearm member adjacent the linkage. The inventionrelates to the combination of means for anchoring the upper arm membersubstantially rigidly to the torso of the wearerby means of a suitableharness or the like and means extending from the leverage means of theforearm member to be anchored to the shoulder adjacent the upper armmember so that the wearer, `even though having no stump, can raise hisshoulder relative to his torso and actuate the leverage means t`o causeswingable rotation of the forearm memberrelative to the upper armmember. In the embodiments of the invention to be illustrated,Y theanchorage of the means extending from the leverage means to the shoulderof the .weareris accomplished by employing a shoulder member in the formof a shoulder cover which overlies the end portions of the shoulder sothat the shoulder may press in the upward direction. The weight of theforearm member may .serve to return it to the normal pendant position,depending upon design characteristics, so that the upper arm member andthe forearm member are substantially aligned beside the body of thewearer.

Other objects of the invention will be revealed by a study of thefollowing specification taken in conjunction with the accompanyingdrawings.

In the drawings- Figure l is a view of an artificial arm fashionedaccording to my invention with the shoulder member removed, the forearmmember thereof being partially cut away to reveal the means employed formounting an artificial hand, the arm being shown in the normal or unbentposition. This View is taken in a direction looking toward the innerside of the arm and into a suitable harness device which is used forfastening the upper arm member to the torso of the wearer.

Figure 2 is a plan View of the arm of Figure 1 showing the shouldermember assembled therewith and partially cut away to revealcharacteristics of the internal structure. In this figure, portions ofthe upper arm member and the harness for anchoring the same to the torsoare shown in chain lines. From the nature of the disposition of thecomponents, it will be apparent that a right arm is illustrated havingthe components arranged in a position comparable to a front View of aperson having the palm of the hand turned forward.

Figure 3 is a sectional view of one form of `gripping means in the formof an artificial hand suitable for use with my invention.

Figure 4 is a sectional view of the wrist portion of the arm of Figure1, looking in the direction of the arrows 4-4.

Figure 5 is a perspective View of a tool mounting block which may bemounted in the forearm member in place of the artificial hand of Figure3 to serve as another form of gripping means.

Figure 6 is a more detailed View of the hinge means shown in Figure 2connecting the upper arm member and the forearm member, being partiallycut away to reveal adjusting means whereby the upper arm member, thehinge means, and the forearm member are adjustable relative to oneanother.

Figure 'l is an enlarged partially cut away view of a portion of Figurel showing the hinge means and leverage means along with adjusting meanstherefor.

Figure 8 is a cutaway perspective view of the 3 lower end of theshoulder member indicating adjusting means for the same.

Referring now to the drawings, and more particularly to Figures 1 and 2,it will be observed that my artificial arm is comprised of an upper armmember l and a forearm member ll connected by the hinge means l2. Theupper arm member lil is designed to be anchored to the upper portion ofthe body of the wearer by the body plate i3 which has suitable straps i4and I5 designed to pass around the body of the wearer and fasten in aconventional manner. A strap i6 isalso provided which extends from thebody plate 13 to pass over the opposite shoulder of the wearer andwhich, therefore, must be shaped and tted according to preference.

A shoulder member sleeve I1 fits slidably within the upper arm memberli] as indicated in Figure 2 and carries a shoulder plate i8 designed tofit over the adjacent shoulder of the wearer. It is ter being coaxiallymounted on the shaft 22 of l the hinge means i2, means (to be describedhereinafter) being provided in the forearm member ii for xing thetoothed segment 2| relative to the forearm member. It is thus apparentthat axial movement of the upper arm member I 1 within the upper armmember le? will cause swingable movement of the forearm il about theshaft 22 relative to the member Eil, by means of leverage develop-edthrough the toothed segment 2i with the shaft 22 acting as a fulcrum.

rJChus a novel method of actuating an artificial arm according to theinvention is effected since when the upper arm member i@ is anchored tothe torso of the wearer by a body plate i3, it remains substantiallyimmovable relative to his torso. Neglecting for a moment, the structureof the shoulder member of Figure 2, it will be apparent that if oneshand could be inserted into the upper arm member to grasp the adjustingrod I9 which connects to the leverage means involved in the toothsegment 2l, then a pulling of this rod would cause the forearm member lI toI swing on the hinge means i2 relative to the upper arm member.According to the invention, means are provided for connecting theleverage means described to the adjacent shoulder of the wearer, suchstructure involving generally the shoulder member i1 adjustablyconnectable to rod I9 and which extends to mount the shoulder plate I8which rests over, and substantially covers, the

adjacent shoulder of the wearer. It Will be apparent that if adjustingmeans are provided whereby the wearer can fasten the upper arm memberand shoulder member components to his torso and adjacent shoulderrespectively so that when the adjacent shoulder is depressed, relativeto his torso, and the forearm member is pendant in the normal downwardlyhanging position, then upon raising his adjacent shoulder, the shouldermember will be raised upwardly of the upper arm member to cause theforearm member to swingably raise. Not only does the invention hereinembody essential structure which takes advantage of this novel method ofactuation oi an artificial arm, but relates also to a member ofadjustment expedients by virtue of which an artificial arm may befashioned to more nearly simulate the normal capabilities of the humanarm.

f The free end of the forearm member Il mounts suitable gripping means22a as indicated in Figs. l and 2, which show an artificial hand, thestructure of the latter being more specifically illust-rated in Fig. 3.The body of the hand 23 has a mounting block 24.- eXtending therefromand designed to be accommodated in the receiver 25 of the forearm.member Il and fastened therein by locking screw 26, engaging thedepression 26a in the block 24. The body of the hand 23 mounts aswingable thumb member 21 pivoted as at 28, the lever arm 29 of thethumb 21 being connected by a suitable link 30 to a shaft 3l mounted inthe block 24 to provide gripping pressure in the thumb by the springmeans 32 engaging the washer 33. The adjusting nut 34 riding thethreaded portion 35 of the shaft 3l provides a simple and efficientmeans of adjusting the necessary gripping pressure of the thumb 21relative to the body 23 of the hand. Suitable finger members 35 extendfrom the body 23 on either side of the thumb member 21 substantially asindicated Fig. 2.

Where the operator desires to handle certain specific tools, a block 31(Fig. 5) may be provided which is designed to be mounted in the receiver25 instead of the artificial hand formerly described, the form shownhaving a through bore 33 designed to accommodate the handle of ahaclrsaw, say (not shown), the latter to be securely held by the lockingscrew 39. The block 31 has a depression 2Gb to receive the end of screwE5 and facilitate secure fastening of the block in the receiver 25. Itwill be appreciated that other designs of blocks may be provided whichmount specific tools or, in the alternative, tools may be fashionedhaving a block portion designed to be received and mounted in thereceiver 25.

In order to simulate normal capabilities of the human arm, provision ismade for the axial rotation of the forearm member Il relative to thehinge .means l2 and rotation of the hinge means i2 relative to the upperarm member l0. Referring to Fig. 6 these functions will be evident byobserving that the forearm member I I mounts the sleeve 50, the latterbeing fixed by suitable pins or screws 4|. The lower arm portion 42 ofthe hinge means l2 is in the form of a tapered body 43 which fitsslidably into the inner tapered bore 4d of the sleeve 4E) and mounts atoothed retaining ring 45 at the inner extremity 45, being fixed bysuitable pins 41 and presenting teeth 48 to the locking dog 49 toconstitute adjustable detent means. Relative rotation between the lowerarm portion 42 of hinge means l2 and the forearm member Il isaccomplished through releasing the dog shaft 50 by pulling on a cord(not shown) attached to the draw ring 5I (Fig. 7) against the pressureof spring means 52 and rotating the forearm member l I to the desiredposition and releasing the dog shaft 50 to allow the dog 49 to engagethe teeth 48. It will be apparent that the rotation of the forearmmember relative to the hinge means I2 is a matter of adjustment only andthat the arm remains fixed in a selected position of adjustment. Toadjust the arm to a diiferent attitude, with regard to the rotativemeans discussed, the operator with his good hand may draw on a cordattached to the draw ring 5| and, by holding the forearm member betweenhis knees, adjust to another position of desired adjustment. In someinstances, the amputee may require help to adjust his arm.

Similar rotative adjustment is provided in the upper arm member I5, thelatter mounting a similar sleeve 53 by suitable screws 54, the upper armportion 42a of the hinge means I2 being accommodated in the tapered bore55 and being held therein by the toothed retaining ring 58 fixed to theinner end 5l of the upper arm portion 42a by suitable pins 58. The teeth59 of the ring 55 are engaged by a dog B0 having a flexible type shaftBI communicating to an exterior ring 82 which may be pulled by the goodarm of an operator against the pressure of spring means 53. Thus bypulling on the ring 62 the operator may release the dog Ell and rotatethe upper arm portion 42a of the hinge means I2 relative to the upperarm member I8 to a new position of adjustment and thereafter release thering 62 to allow the` dog Eli to engage the teeth 59, to provide alockingfunction. As shown, the teeth formed on both the toothedretaining ring 45 and the ring 56 extend only half Way around thecircumference of each, providing, in the ultimate, 360 of adjustment inthe gripping means and substantially 180 of adjustment in the hingedmeans relative to the upper arm member. The operator, with his goodhand, may pull on the ring 52 to provide rotative adjustment of thehinge means I2 relative to the upper arm member I8 somewhat in themanner discussed with reference to the adjustment of the forearm memberpreviously described. Therefore, to the extent that the arm may beadjusted for different attitudes concerning the disposition of the hingemeans I2 of the elbow relative to the upper arm member and the rotativeadjustment of the forearm member and hand relative to the hinge means ofthe elbow, the artificial arm of my invention is simulative of thecapabilities of the human arm.

As will be apparent from Figs. 6 and 7 the hinge means I2 are comprisedof the bifurcated arms E4 extending from the lower arm portion 42 andthe bifurcated arms 65 extending from the ,1

upper arm portion 42a, being mounted on the common shaft 22 which alsomounts the toothed segment 2 I, the latter being disposed between thebifurcated arms 5d (Fig. '7). Suitable teeth 6T are provided on theperiphery of the toothed segment 2| and are engaged by a toothed dog 88slidably mounted in the bore `59 of the lower arm portion 42 of hingemeans I2. A portion of the bore 69 is threaded as at 'I0 to carry abushing 'II which slidably mounts a shaft I2 having actuati ing means'I3 extending outwardly of the arm to present an actuating ring 'III toan operator. The other end of the shaft 'I2 is thread mounted in the dog68 as at 15, positive engagement with the dog 58 with the teeth BI ofthe toothed segment 2I being ensured by a suitable spring 1B. Variouspositions of engagement of the dog 68 with the teeth 81 are thereforepossible providing a means of adjusting the sweep limits of the forearmmembers relative to the upper arm member.

In order to provide a means for returning the forearm member to normalposition, the latter being determined according to the segmentadjustment (i. e. the engagement of the dog E8 with the teeth 5l of thetoothed segment 2I) an opposed compression spring 'I1 is provided andmounted on a shaft I8 which is pivotally connected as at i9 to theextended arm portion 8B of the toothed segment 2I. The shaft 'I8 extendsloosely through the bore 8l of the upperarm portl (i tion 42a of hingemeans I2, spring means 'I1 engaging the abutment 82 and being confinedby the washer 83 and pin 84 at the free end of the shaft 78.

Referring to Figs. 1, 2, 7 and 8 it will be observed that adjustingmeans are provided in the shoulder member` whereby the relative distancebetween the operating position of the shoulder of the wearer relative tothe fastening posit-ion of the body plate to the upper portion of hisbody may be adjusted to vary the normal rest position of the forearmmember relative to the upper arm member, that is the position whenhanging freely at the side of the wearer. Thus, in Fig. 2 it will benoted that the link 2U extending from the pivot point 2 Ia on thetoothed segment 2| connects to the bifurcated arms Isa of theadjustingrod I9 by a suitable pin 85, the latter rod passing through a bore 86 inthe closed end 81 of the shoulder member sleeve I'I. A gear 88 suitablythreaded for reception on the threaded shaft I9 (see Fig. 8) serves as ameans for adjusting axial position of the rod I9 through the wormadjusting means 88a which may be rotated by a suitable key engaging thestud end 89 which is accessible through a slot 90 in the sleeve I'I anda further slot (not shown) in the upper arm member IB. Free slidabletravel of the sleeve II is insured by rollers Ila (Figure 2) mounted inbrackets I'Ib fixed to the inner surface of the sleeve I'I. The rollersI'Ia extend through oriiices I'Ic to engage the inner surfaces of theupper arm sleeve 53.

It will `be appreciated that through the various adjusting meansprovided, an artificial arm fashioned according to my invention will becapable of movement simulating the capabilities of the human arm.Further, due to the use of a body plate and cooperating shoulder memberwherein advantage is taken of relative movement between a shoulder ofthe wearer and the upper portion of his torso, the present device isoperable from one side of the body only. As previously discussed, theupper arm member remains at all times substantially fixed relative tothe torso of the wearer so that in the structural arrangement described,the wearermerely presses upwardly on the shoulder plate I8 against theweightof the forearm member. If the shoulder is raised with the body,

f as would probably be the normal tendency of a person rstwearing thedevice, the forearm member will not be actuated. The wearer must learnto move his shoulder relative to his torso somewhat in the manner whichis observed when a person hunches his shoulders but, in this instance,only one shoulder is involved. The "hunching is done against the weightbeing lifted. The human body is capable of developing a large force inthe relative manner described and when this principle is applied to theoperation of an artificial arm as shown it has been found that Weightslargely in excess of those which could be lifted by the human arm`onlywith diiiiculty, may be lifted with comparative ease. Moreover, in viewof the fact that operation is dependent upon movements related to oneside only of the body of the wearer, the latters good arm will be freefor efficient cooperation with the artificial arm. It may also bepointed out that the weight of the arm is partially supported by theshoulder member which, due to the design shown, substantially avoidsthediscomforts of chafing and cutting of numerous straps resulting from thewearing of artificial arms of the prlorart.

It is apparent that modifications. may be effected in the specific.design of the shoulder member and its cooperation with the upper armmember from the particular form shown, since changes will be necessaryto meet the requirements for various amputees. t is therefore intendedthat the present disclosure should not be limiting in any Way other thanthat indicated by the scope of the following claims.

What I claim as my invention is:

l. An artificial arm comprising an upper arm member, means for anchoringsaid upper arm member to the torso of an amputee in a positioncorresponding to the location of the upper portion of the severed armand in a substantially fixed position with regard to the torso, aforearm member pivotally connected to said upper arm member insimulation of an elbow joint, a shoulder plate mountable on the adjacentshoulder of the aniputee, leverage means connectable to said forearmmember for movement therewith about said pivoted connection, andmovement transmittingmeans connecting said leverage means and saidshoulder plate, whereby upward movement of said shoulder is transmittedby said movement transmitting means to said leverage mechanism andforearm member to cause movement of said forearm about said hingedconnection relative to said upper arm member'.

2. An articial arm comprising an upper arm member, a forearm member,hinge means operatively connecting the upper arm member to the forearmmember, means for fastening the upper arm member to the torso or" thewearer to hold said member substantially fixed with regard to the torso,leverage means for actuating the forearm member about said hinge meansand having a fulcrum coincident with the axis of said hinge means,shoulder engaging means mountable on the adjacent shoulder of thewearer, and movement transmitting means connected to said shoulderengaging means and attached to said leverage means at a point spacedfrom said axis, whereby relative movement between said shoulders of thewearer and his torso causes swingable movement of the forearm memberrelative to the upper arm member about said axis.

3. An artificial arm as claimed in claim 2, and adjustable detent meansmounted on said forearm member and engageable with said leverage meansfor adjusting the sweep limits of said swingable movement of the forearmmember relative to the upper arm member.

4. An articial arm as claimed in claim 2, adjustable detent meansproviding rotative adjustment of the forearm member relative to thehinge means, and second adjustable detent means providing rotativeadjustment of the hinge means relative to the upper arm member, wherebythe forearm member is capable of rotatable adjustment to simulatevarious attitudes of the human arm.

5. An articial arm as claimed in claim 2, means providing rotativeadjustment of the forearm member relative to the hinge means, meansproviding rotative adjustment of the hinge means relative to the upperarm member, said rotative adjusting means for the forearm membercomprising a toothed retaining ring operatively connectable to the hingemeans, a tapered sleeve forming the outer portion of the forearm memberand rotatable relative to the toothed retaining ring and hinge means,and a spring retained dog carried by said tapered sleeve and engageablewith the toothed retaining ring to hold the latter in a desired positionof rotative adjustment re1- ative to the sleeve, and the said rotativeadjusting means for the upper arm member comprising a second toothedretaining ring connected to the hinge means, an outer cylinder formingthe outer portion of said upper arm member and rotatable relative tosaid second toothed retaining ring, and releasable means carried by saidouter cylinder and adapted to engage the teeth of said second ring forfixing the second'ring in a selected position of rotative adjustmentrelative to said outer cylinder.

G. An artificial arm comprising a forearm member, an upper arm member,hinge means providing a hinged connection about a hinge axis betweensaid two members, a body plate attached to said upper arm member, meansfor securing said body plate to the torso of the wearer in asubstantially xed position with respect to the torso, a leverage segmentcoaxial with said hinge means, means interconnecting said leveragesegment with said forearm member to cause said forearm member to movewith said leverage segment, a shoulder member mountable on the adjacentshoulder of the wearer for movement with said shoulder, linkage meansconnecting said shoulder member with a rst portion of said leveragesegment spaced from said hinge axis for causing movement of saidleverage segment and said forearm member about said hinge axis relativeto said upper arm member when said shoulder is raised with respect tosaid body plate and upper arm member, and resilient means mountedbetween a second portion of said leverage segment and said upper armmember in opposition to such movement of the leverage segment andforearm member.

7. An artificial arm as claimed in claim 6 in which said shoulder membercomprises a sleeve, a shoulder plate attached to the upper end or thesleeve, and an apertured closure at the lower end of the sleeve, saidlinkage means including an adjusting rod passing through said aperturedclosure and operatively connected to said iirst portion of said leveragesegment, and

means for adjustably nxing the amount of protrusion of the adjusting rodthrough the apertured closure to vary the normal rest position of said'forearm member relative to the upper arm member.

8. 'An articial arm comprising a forearm member, an upper arm member,hinge means providing a hinged connection about a hinge axis betweensaid two members, a body plate attached to said upper arm member, meansfor securing said body plate to the torso of the wearer of the arm in asubstantially xed position with respect to the torso, a leverage segmentcoaxial with said hinge means, means interconnecting said leveragesegment with said forearm member to cause said forearm member to movewith said leverage segment, a shoulder member mountable on the adjacentshoulder of the wearer for movement with said shoulder, linkage meansconnecting said shoulder member with a rst portion of said leveragesegment spaced from said hinge axis for causing movement of saidleverage segment and said forearm member about said hinge axis relativeto said upper arm member when said shoulder is raised with respect tosaid body plate and upper arm member, and resilient means mountedbetween a second portion of said leverage segment and said upper armmember in opposition to such movement of the leverage segment andforearm member, said shoulder member comprising a sleeve, a shoulderplate attached to the upper end of said sleeve, and an apertured closureat the lower end of the sleeve, said linkage means including anadjusting rod having a threaded portion and passing through saidapertured closure, means connecting said rod to said first portion ofsaid leverage segment, and means for adjustably fixing the amount ofprotrusion of said adjusting rod through the apertured closure in thedirection of the hinge to vary the normal rest position of said forearmmember relative to the upper arm member, said last named meanscomprising a nut having peripheral teeth and rotatably mounted on saidthreaded rod portion, said nut being positioned adjacent said closure tolimit movement of said rod in the direction of said hinge, and arotatable worm adapted to articulate with said teeth to provide meansfor rotating the nut on said rod,

R. W. WILKINSON,

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 370,774 Fuller Oct. 4, 1887423,840 Ulmer Mar. 18, 1890 1,273,461 Corley July 23, 1918 1,387,133Dorrance Aug. 9, 1921 2,409,884 Mollenhour Oct. 22, 1946 2,415,145Mollenhour Feb. 4, 1947 2,428,632 Mollenhour Oct. 7, 1947

